It is known when capturing a sequence of images of a scene which are to be combined into a video stream that motion of an object within the field of view can cause problems with the perceived quality of the video stream.
Referring to FIG. 1(a), in a brightly lit scene, each frame can be captured at say 24 fps with a short exposure time (SET), say 1/500s, and so an object such as a football in this case will be captured as a sharp image portion at a sequence of discrete locations within each frame. In FIG. 1(a), numerals, 10-1 . . . 10-4 indicate the position of a ball moving across a scene in a sequence of four SET frames. When a video stream including frames acquired in this fashion is played, the motion of the ball will appear disjointed and unnatural.
Referring to FIG. 1(b), if on the other hand, each frame is captured with a longer exposure time (LET), say 1/50s, then although motion of the ball through frames 11-1 . . . 11-4 will appear smoother, the scene will tend to be overexposed with many saturated areas and so loss of image detail.
Even in an acquisition device with variable aperture, closing down the aperture rather than speeding up exposure time to solve motion problems would cause problems with depth of field.
Separately, it is known to use Neutral Density Filters to reduce the amount of light entering the lens, so increasing exposure time and introducing blur into video frames. However, good quality neutral density filters are expensive, they cannot be added to any kind of camera, and they are not designed to be used by casual users.
ReelSmart Motion Blur (http://www.revisionfx.com/products/rsmb/overview/) introduces motion blur into images which have been acquired with a relatively short exposure time, but this does not address problems with scenes which require a high dynamic range and so leads to problems with underexposure or saturation.
High Dynamic Range (HDR) images are typically generated by acquiring multiple component images of a scene, each with different exposure levels, and then later, merging the component images into a single HDR image. This is a useful way of synthesizing an image of a scene comprising very dark and very bright regions.
HDRx from Red.com, Inc. (http://www.red.com/learn/red-101/hdrx-high-dynamic-range-video) includes a “Magic Motion” facility which interprets different motion blur characteristics from a pair of frame sequences, each simultaneously acquired with different exposure times, and then blends them together under user-control.